/// <summary>
/// Creates a command parser for a <see cref="CommandSymbol"/>
/// </summary>
private static Parser <LexicalToken, Command> CreateCommandParser(
CommandSymbol symbol,
Parser <char, Parser <LexicalToken, SyntaxElement> > commandGrammarParser)
{
Parser <LexicalToken, Command> commandParser = null;
try
{
var result = commandGrammarParser.Parse(symbol.Grammar);
var customParser = result.Value;
if (result.Length != symbol.Grammar.Length)
{
Ensure.IsTrue(result.Length == symbol.Grammar.Length, $"control command grammar {symbol.Name} failed to parse fully at offset ({result.Length}): {symbol.Grammar}");
}
if (customParser != null)
{
commandParser = Rule(
Token(SyntaxKind.DotToken),
customParser,
(dot, custom) => (Command) new CustomCommand(symbol.Name, dot, custom))
.WithTag($"<{symbol.Name}>");
}
}
finally
{
}
#if DEBUG
if (commandParser == null)
{
throw new InvalidOperationException($"invalid command grammar: {symbol.Grammar}");
}
#endif
Ensure.NotNull(commandParser, $"invalid command grammar: {symbol.Grammar}");
commandParser = commandParser ?? Match(t => false, lt => (Command)null);
return(commandParser);
}
/// <summary>
/// Gets the parser for the command.
/// </summary>
public Parser <LexicalToken, Command> GetCommandParser(CommandSymbol command)
{
this.commandToParserMap.TryGetValue(command, out var parser);
return(parser);
}